Chrysler 300M Starting/Stalling problems

Comments

littlemikey : These are probably the reasons why the seller was selling the car , but they never mean that the car is no good at all. Sure , it's a real letdown , but all you have to do is begin a process of ellimination to bring the engine back to it's former self. Judging by the fact that you said you drove it around the block or so ( I would always insist on driving the vehicle on a highway or subhighway to see if the engine performs as normal at higher speeds) , chances are the engine is in need of either a crank sensor or a cam sensor - if either one of these is not functioning correctly , the engine will run rough and present stalling characteristics. But , before considering these sensors , make certain that the engine has the correct sparkplugs for the car (no aftermarket types). Many owners have fallen prey to the aftermarket sparkplug manufacturers , and found that their engines will not run correctly (only to expect to return the plugs to a parts store). So ... checking which plugs are in the engine is paramount. Especially (as is in my case with my 2002 300M Special) , if your engine requires Laser Platinum Sparkplugs.

After confirming which plugs are in the engine , you must also consider their age. The Laser Platinum Plugs are supposed to be good for 60K miles , but they should be replaced within 3~4 years of use. Once the plugs are OK , the first safe thing to do is to pour a small amount of gasline antifreeze into your gastank - as this will mix with any water droplets which cling to the insides of the gastank inner walls , which makes them get burned through normal flow. Hopefully you don't have injector problems , as some owners will pour in any type of solution that a label states is guaranteed - yet they may find their engine not running , and have no success getting the advertised guarantee looked after. Then they sell the vehicle in frustration.

Since it appears that the engine was OK when it was relatively running at a moderate temperature in a short slow speed drive - there could be a problem with 1 or more of the sparkplug coilpacks (which each sparkplug has instead of a single coil that feeds all sparkplugs). This is something to consider where electrical faults can cause incorrect readings to be sent to the computer or other related modules etc. (and cause a flickering or on off condition with a "check engine" light etc.)

If you find that it appears that there is no such problems , you might seriously want to check the main battery cables that go over the rear of the engine and rest upon , or are mounted to the transmission case for wear. In some cases I have found that both the positive and the negative cables go over the transmission together in a single sheath. Through time , chaffing of the cable insulation can occur , and cause intermittent shorting. This shorting can make it so that the starter is not reliable , the lights flicker or don't work all the time , or they can even cause the engine to be effected by intermittent power connections to the battery - because if you take a battery cable off , the engine stalls. Not everybody checks this. And it is not uncommon to find as much as 2" of area where the cables are both bare , causing a random or semi-random short (such as when they heat up).

So... you have to do a few things to find out if you can resolve the running problem/s. The blinking oil light , may be because of a faulty oil sensor , and it could also mean the oil pump is worn out. The only things you can do to resolve that is to firstly , change the oil and filter (check if light comes on or not) , and if it does - then change the oil sensor , and check again. If all fails , the oil pump may be gone. Ticking sounds coming from the upper portion of the engine are usually worn or sticking tappets/lifters , which can be changed by removing the valvecovers. But , if the oil is dirty , has not been changed regularly , they become sticky from carbon etc. Hopefully they haven't started ticking because the owner had a very heavy foot or drove the engine to it's maximum at all times etc. If so , you will need new lifters on both sides of the engine , which is not really a cheap job when done at a service station - because the whole front cover has to be removed from the engine as well etc.

Hi there again. I changed the oil and oil filter and filled it with new oil. Then I started the engine up and there is still a loud ticking noise coming from the top of the engine. When I rev up the engine it gets louder. I read in one of the forums that there could be build up on the end of the tip of that goes inside the oil pan ( sludge ) keeping oil from being sucked up to the top of the engine. Is this possible? It looks like the tube that goes inside the oil pan is like six inches above where you drain the oil. Do I just loosen the nut that secures around the tube and pull it out and check for sludge build up? How can I tell if the oil pump is no good? Any help would be appreciated. Thanks again, Mikey...$

I would take this to a place thatrebuilds engines and let them listen.

This sounds ominously like your enginesludged up around one of the bearingsand the bearing has overheated and deformed. The deformation of the bearingmakes it harder for the engine to spin at idleonce it's up to speed/temp.

This happened to me and I had to replacethe engine. You can also have it rebuiltfor about $3k.

The big question and possibly the clue is that when you first drove this car , there wasn't a problem with loud ticking coming from the heads or thereabouts. I guess I can rule out that you immediately took this car for an all out racey spin - where you dropped the hammer and buried the needle sort of thing right after you were the owner. This type of thing is the worst thing you can do when you buy a used/older vehicle. You have to assess it's condition etc.

Being that it wasn't doing so , makes me believe that the problem can't be major - as 99% of the time a damaged engine will repeatedly show it's condition full time. Something happened between the time you test drove it , and the time you drove it home. With these things in mind , it sounds alot like the oil pickup tube (sump tube) is being blocked by something that is moving within the oilpan. The oilstick check tube is not part of the oil pickup tube , so the only way to determine if the oilpan pickup tube/sump pump tube is periodically being blocked/restricted - is to remove the oilpan from below. This can be done on the 300M's , but each year is different , and - you may have clearance problems , if you are not inclined to reach inside a tilted oilpan and unbolt the mounting bolts that hold the pickup tube (which has a ladel type/sump type attachment that resides near the bottom of the oilpan when suspended in position). Let's just say , you take the transmission / oilpan support bracket off , and you unbolt the oilpan. You might find clearance problems and not be able to see quite clearly inside the oilpan enough to see that the shape of the oilpan dictates the size/length of the pickup tube , and it's "end cup". But - if you reach in and feel the whole thing , you can determine if the cup has seperated into 2 pieces (which it can do). It is possible , that the cup bottom has come away from the top section (which the tube is part of , where it extends upwards and bolts to the engine block inside the pan). With some mechanical fortitude you can feel if this has happened and know that it will only take a few bolts to release the whole part (sump pickup tube).

I have done this a few times , and once found a Toyota that had a loud knock at initial startups (but ran fine after I tuned it up) - so I pulled the oilpan out by removing the crossmember bolts and dropping the crossmember. Low and behold (as I suspected) , a small 1" piece of (what was part of what is called a "driptray" , was constantly lodging itself right under the sump pickup tube. Each time the pump sucked oil up , it immediately went right to the end of the tube , and blocked oilflow. A oilpan driptray is a skirt that surrounds the sump pump cup , and prevents oil from dripping off of any moving parts above from creating bubbles in the oilpan while the engine is running. But - a portion of the skirt / driptray was no longer welded to the inside of the oilpan , AND , this small but strong piece of metal broke away from a sharp hanging corner of the front of the driptray. I replaced the oilpan , set everything back in place - and that car ran for over 2 years , started fine in winter , and never knocked again. In fact it sold in about a week , after the owner I fixed it for bought something else. This Toyota was painted by a mechanic friend who painted the entire sealing of one of the GM plants , after I did the engine and bodywork , which was extensive - but simple , by standards.

It might be a good idea to take your car to someone who can check the oilpan pickup tube , and it's assembly before you take it to an engine rebuilder , because - most engine rebuilders will take the opinion that the engine is gone/has major internal problems etc. In effect , by going through the oilpan - "is" , checking the other end of the oilpump , because where the oilpan pickup tube attaches to : is the oilpump draw tube or the oilpump itself / or it's connecting area (every time). Basically , you are doing what most won't. BUT ! You know the car was fine for a little while , so that should tell you (as I said) , it is NOT MAJOR.

So ... basically , what you may have , is a engine with a defective sump pump cup - while "this is a big deal"? I don't think I would spend thousands for a loose piece of metal inside the oilpan - before I asked a mechanic to check to see if that apparatus is OK. Especially when the service manuals show that the engine oilpan can be removed without much trouble (although this varies with model year and possibly type : IE - Special etc.) In your case I think it is especially important to remember that the engine was fine , and know that as you speed the engine up , more and more oil is pumped upwards through the engine block. This increases the oil pressure : and very well - CAN dislodge any loose pieces of debris or metal from within the oilpan. That is a fact.

hi there again. I changed out the spark plugs and I changed the oil and oil filter but the car is still making loud knocking at the top of the engine when you start it up and let it run. It gets louder when you rev up the engine. any suggestions? is this a process of elimination? thanks again.Mikey...$

It is a process of elimination , since when you bought the car and drove it for the first time - none of the noise was there. As I said you have to start with the rudementary things unfortunately to determine what you'll have to do. OK , so you checked the oil and filter , and the sparkplugs (no joy) , what about the coolant (it could be as old as the vehicle) , AND - it must be yellow in colour for the all aluminum engine. Coolant does apply since you drove it a bit , and then had later problems at the lights , and sudden ticking or loud noises. Knocking is a very bad sign though - as that could mean main bearings or connecting rod bearings are worn out. But , knocking as I mentioned before can be due to a "no oil" or low oil pressure condition. It is possible as well , that the seller put some kind of thick oil additive in the engine so that this ticking or knocking would be limited for a short period of time. (Always drive the vehicle on a major highway when you buy any vehicle - if the seller says no , or makes excuses that this is not possible , that is a sign that there may be something wrong with the vehicle's engine).

At this point , I am still of the opinion that such serious knocking or bad ticking problems cannot be hidden completely simply by doctoring the oil. And these types of overnight problems when buying are 1 of 2 things. The seller knew about it and did something to hide the fact - or - the engine is not getting proper oil at all. Even if I was completely incorrect - that would mean you need another motor. It's much better to spend $200+ on finding out - than to scrap a perfectly good engine , that may have oil pan / pickup tube or oilpump problems. So... after the coolant check , you'll have to pull the pan down and hope and pray that you find some sort of debris or loose pickup cup in the oilpan. Most people just give up , after they have a few diagnosis' - that the bearings are gone etc. Which can be a costly mistake , as rebuilt engines don't necessarily mate perfectly with automatic transmissions. And - we are talking about a used or remanufactured engine being bolted to a worn transaxle transmission that works far differently from inline transmissions on front wheel drive vehicles where both the engine and transmission are mounted from side to side. The 300M is mounted like an 8 cylinder motor - straight in. I'd be doing everything I could , including reaching into the oilpan and pickup tube setup before I spent any other money on , what is , if you get another engine , just a frame and transmission.

This all hinges on the fact that you bought the car , and found it to be OK. You trusted your instincts , and the vehicle was OK - so I have to say that you should stick to your guns for the time being , until you absolutely know whether or not you simply have an oilpump or oil related problem. As far as timing belt etc. goes at the front of the motor , that , along with any sort of coilpack problem should be ruled out - because , if an engine has timing belt or coilpack problems - they are always present (at all times) , whether the engine is cold / warm or hot. You have , what I call : "a changeling" , first it didn't have problems , and then it did. I'd be thinking about that until I had the oil sump pickup in my hands to confirm the oil pickup was OK , and there wasn't anything in the oilpan that could have caused a temporary or intermittent oiltube blockage.

If you are so inclined , you could also pull off 1 of the valve covers and run the motor without it on - to confirm a dryrunning (no oiling) condition. This would be simple enough. If it appears that no oil is getting to the top of the motor , then the lifters will click loudly. If oil is sqirting all over the place , then you know the oilpump is good , and not restricted.

So , basically , I have suggested a top to bottom check (in that order). If you have the valve cover off , and start the engine while no oil appears anywhere across the cam or valves , then YOU DO HAVE A OIL PICKUP TUBE RESTRICTION. Firstly , a piece of something was able to move around and periodically come in contact directly at the pickup tube end (some have screens) , but at this point it would be clear that the piece has now permanently lodged itself in front of the pickup tube. Just like when you have a vacuum cleaner hose , and you put something in the path of suction. It will remain there as long as there is suction , but if it's lodged there , it will not let go when suction stops. Which would mean you have found your parallel (first the piece was not in direct contact with the screen or pickup tube , and then it somehow was). This is possible , and highly likely if there is no oil getting to the top of the motor. Ask yourself how the motor ran at all without any noise again (if no oil was ever getting to the top of the motor). Which brings up another possibility. The previous owner had this problem , and poured oil directly into the valve cover , just before you went to test drive it. Which would - drain to the oilpan eventually (and the top of the motor wouldn't have enough oil circulating again) , which is when you noticed the noises , and stalling. You'll have to judge , by whether it is running dry , or with just a few specks of oil now and then , which is very inadequate. It must be squirting repeatedly to keep the valves and the cam lubricated.

2001 chrysler 300m with 150,000 miles. Last January (10 months ago) my daughters car wouldn't start. All I heard was the starter solenoid click. So it sat in my driveway 3/4 days til the weekend. I went out and it started right away. A week later it did it again so I put it in the garage and pulled starter. Cleaned it and wires up and had 3 shops do there free test on it and it was good. Replaced it and no problems til yesterday. Then the solenoid will click 10-15-20 times and then start. Before this all happened the battery was replaced nov 2012 and the positive battery cable to the jumper from battery was replaced October 2012. Cleaned any connections I could and don't see any thing loose. Not sure if moisture has anything to do as don't remember weather last winter on that day other than being cold but it was raining pretty hard here in northern Wisconsin yesterday when it started again.

This sounds like the exact symptoms of battery cables which are contacting each other inside the sheath that covers the battery cables together where they go over the transmission. This can be a bit difficult to determine because what happens is : the 2 large cables rub themselves on each other from vibration , and the friction wears away the black cable insulation. Which , if this is the case - you can't see any damage to the sheath. Sometimes both the cables and the sheath are worn through somewhere behind the throttlebody assembly , and down on top of the transmission casing - behind the engine , closest to the firewall. It sounds like it would be a good idea to cut the sheath off , and inspect the battery cables for wear / contact / short. This would explain the intermittent short , because if the cables have bare wire showing , they will corrode (because of arcing as well) , but when the car is warm/hot or moving - this wears clean areas at the exposed areas , which makes the short reoccur. Once an old exposed area starts to short again - proper connection to the starter , which is where the cables are going , fails.

It is probably too late now but , I usually fully check the entire lengths of each battery cable (remove all sheaths / covers etc.) , whenever I have a starter out. While it is easy to slide the sheaths over the small end connectors of battery cables. Any hidden areas where the battery cables go are suspect and should be inspected/cleaned , at least. Several times I have found positive battery cables hanging on by just a few strands of the entire cable - even at 2 points on the same cable. This explains a loss in current flow , and possible or intermittent shorting. In today's vehicle electrical systems , this will cause the computer and it's modules to get incorrect readings/voltages , and react incorrectly , or in an odd way. Plus , the ASD Relay can be triggered or fail to allow connection. The : Automatic Shutdown Relay protects the electrical system from overload , when it is tripped by overcurrent. But it also requires a minimum of voltage to allow the vehicle to start or run. This occurs when the key position is in the "run" position , just before you turn the key to the "start" position.

Battery cables of this sort on the transmission casing or other aluminum parts are like this because aluminum is not a good conductor of electricity , as opposed to steel or copper. So... they are intermittent and low level shorts , which may only spike or become a problem (or conduct enough) sporatically/seldom. IE : after running the car on the highway , or when alot of extra electrical systems are being used : like a combination of windshield wipers/high beam headlights/heater/rearwindow defroster and the heated seats in winter conditions.

I will check the cables this week. I replaced the starter relay as a cheap check but didn't help. The positive cable I replaced last year was only holding together by a few strands. I'm also am thinking electrical not starter because I had starter out already and it worked after I put it back in thinking I corrected a loose connection. I will put it up on ramps tomorrow and see what I can find. Why would this be happening so far apart by months?

This could be a ground problem , as there appears to be some confusion or errors in the authentic service manuals that show where a ground cable should go directly from the battery negative terminal to the engine block itself. This is the norm , but my 2002 300M Special has no such animal attached to the engine block. I will be adding it just to be on the safe side even though there are no problems. Also : my 2001 Dodge Durango SLT 4.7L V8 Magnum has a couple points at which the negative battery cable bolts directly to it's cast iron block. The 4.7L has aluminum heads , and a cast iron block , but the 300M's have an all aluminum engine. So... while grounding to aluminum is already limited - attaching a ground cable directly from the battery to the aluminum engine block may help. Intermittent power is one thing - but intermittent ground is like having a loose component or connection.

Another reason you could be having starter problems , could be due to a faulty transmission range sensor (TRS) or a bad park/neutral position switch. What I am suggesting is that there may be a problem because the vehicle is not actually in PARK , to allow the starter to turn the motor freely. If you had this problem , and the solenoid connected the starter (clicked) , it wouldn't be able to turn both the engine and the transmission (considering the transmission is not fully in neutral , or PARK .)

To check if the transmission is not fully going back into PARK , while attempting to start the car , rock the car back and forth to see if it actually engages the starter at some point. If it does , that doesn't necessarily mean it is electrical. Because the 300M transmission also has 2 other variables to consider. 1 is that when the vehicle is in PARK , you are not supposed to be able to depress the shifter button and move the transmission out of PARK , unless you press the brake. This is a safety feature. If you CAN move the shifter without pressing the brake , the system is not set correctly , and can cause starter engagement problems , and/or shifting problems. 2 is that the transmission also relies upon the correct setting of the shifter , and it's relationship with the brake pedal setting. It is possible then , that if the brakes were worked on , that the brake pedal setting is a bit off , which can cause these starter problems - because of both mechanical and electrical appartuses not working correctly together.

At the shifter , it must remain set correctly , and at the brake pedal , it must be set correctly for the system to function properly. This is what can throw off the sensors as well , when their signals are not correct.

When the engine is not starting of course , this is a bit difficult to determine - but if you can get in the car and move the shifter out of park without touching the brake pedal - that is part of the problem. And if you do get the engine to start , check the brake pedal interlock first thing , to see if the setup is correct. That the shifter should refuse to move out of park , until the brake pedal is pressed. If this is OK , then you should look at the electrical portion/s at the transmission. IE : Transmission Range Sensor (TRS) , or PARK/NEUTRAL POSITION SWITCH. These send signals to the Body Control Module (BCM) , and if any one of them is not doing so - then the system is not recognizing that the vehicle is either IN PARK , or NOT IN PARK or NEUTRAL respectfully. If you have invalid fault codes - then you have transmission sensor problems. When invalid fault codes are present , the sensor is not functioning properly , as opposed to a determinable fault code , that pertains to a faulty transmission sensor of some sort.

One such example of causing simple problems that become major : is when somebody changes the shifter in the center console. They might alter the setting of the shifter linkages etc. and not know that this will adversely effect the system on the 300M. IE : the shifter is not sensed as being in PARK , the signal sent to the BCM is invalid or incorrect (Reverse) , so the starter will not reliably engage. Because you must be in either PARK or NEUTRAL to start the engine , while the signal is incorrect - the actual transmission's mechanical position can be just a bit off , to where a small tab or locking pin etc. may be unable to engage (lock). When you rock the vehicle , it may go in or lock.

checked all cables i could and they looked ok. Couldn't see behind motor by firewall. There are no fault codes for transmission and will not move out of park without brake depressed. Just got it to start again for first time in 4 days and put it up on ramps. am going to remove starter again and go from there. might borrow ohm meter to test power at starter. Where do the pos and neg cable run to from the 2 jump start blocks above the hidden battery. And on the ground wire there is a mesh wire running from neg jumping block on passenger wheel wheel to the block. looks ok also.

So far so good , but you have to dump the idea/s that an ohm meter will tell you if there is a problem with the 2 cables (that are sheathed together) , that go over the back of the motor/transmission , near the firewall. Reason being , as the cable might only be shorting when there is vibration from either the engine running , or when you hit bumps in the road etc. You have to physically eyeball the insulation on both of those cables. Chances are they have at least 1 area where they are able to touch each other and/or the aluminum transmission casing. The 2 cables are going to the starter , where the ground cable attaches to 1 of the starter bolts and the aluminum transmission casing at the same time. This provides a poor placement for a reliable grounding to the engine , because it is so low and open to corrosion - plus in this case , it is being relied upon for engine ground? It is much better to attach a cable directly to a point on the engine block itself that does not corrode easily for ample ground (then you only have to check/recheck your positive battery cables for corrosion etc.). If you don't want to remove the starter and it's cables , you can always carefully cut the wide covering sheath , (check it) , and then ziptie it back together etc. As far as how the wiring goes as follows , according to the 2001 300M Service Manual : positive battery terminal mount has 2 cables attached. 1 goes to the positive jumper block , and the other goes across the front of the motor to the Powertrain Control Module (PCM) [Transmission Module] & Power Distribution Center (PDC) - which is where there are wiring harness connectors attached to lines that go directly to the starter solenoid. From the positive jumper block , the opposite side of the jumper block cable goes into the sheath at the rear of the motor ( along with the fender mounted cable that comes from underneath the negative battery jumper cable mount). Which means there are actually 2 negative cables that are at the negative jumper fender mount. 1 goes from the battery to the fender mount , which has a permanent type (notched) negative cable that comes from the sheath.

The rudementary diagram shows how there is a positive wire that goes from the #87 portion of the starter relay to the starter. But this is actually a cluster of wires that have connectors on them that snap onto the solenoid plug-in's. These would be the starter switch etc. Ground is connected to the BCM , Body Control Module , so... when you turn the key to the run position , the BCM is already supposed to be grounded , or ON. This is how you get your dash light indicators. If the ground has a short , any number of problems can occur. When you turn the key to the start position , you have switched the starter switch to enable the starter power wire through the #87 portion of the starter relay. While the service manual definately shows that a ground cable is connected as I said , to the rear of one of the starter bolts.

As I said , if the 2 cables that go over the transmission are bare and touching each other intermittently , the BCM /PDC/PCM and other modules are all effected. They are respectfully : Body Control Module , Power Distribution Center & (most importantly - the Powertrain Control Module). If the Powertrain Control Module is effected , it will not recognize the PARK position and allow the starter to power on or turn. All battery outputs , of both negative and positive are monitored before any activity is allowed to occur. This is how the ignition occurs , with no distributor , but is safegaurded/calibrated & repeated (which creates an electronic rotation).

Not that I like to repeat myself but : any time there are electrical related problems , I always check the battery cables (especially to include the portions where there are 2 battery cables coming together) first. Because any diagnostic device can also be effected by this type of short. It is a "source short". Misdiagnosis can repeatedly occur on any metering device if you don't - and many good electronics parts can be repeatedly replaced for no reason as well , along with other repairs that are still effected by this type of shorting. Sometimes there are spacers at these areas where you can clearly see their condition - but as soon as I see any areas where I can't see them (their overall "dual setup") , I remove whatever is in my way to see them - and I usually find bare wires. While the service manual will only include that you "check the battery cables" , where a starter motor is going to be tested / has problems etc.

I checked as much of the cables as i could and they looked good.After talking to a few people that had starters tested and put back in thinking they were good only to replace them and problem solved I removed it again.I had it tested at 2 different places and was given the green light at both auto parts stores. Auto Zone even gave me a printout of what to check which contained alot of what you have said. I purchased a new re-manufactured starter and it has started the ten or so times I tried it. Going to cross my fingers because thats what the old one did when I pulled it in january and it worked after reinstalling it for about 9 months. Thanks for your help!

I have spent over 3 hours searching the internet for the cause of my problem. My 01 300m will run great, but when it warms up it will stall when coming to a stop, especially after highway driving (over 45mph). I was ready to throw the whole works at it; crank sensor, cam sensor, IAC motor, Map sensor, EGR valve, torque converter solenoid, etc. But I was pretty settled on it being the IAC motor. I've had these go out on a few other cars before. I decided to humble myself and take it to my mechanic (not dealer) and he hooked up the Snap On scanner and noticed that it was very low on vacuum. He knew to unplug the map sensor that is on the plastic intake on the top of the motor on the drivers side, and it died. He then plugged it back in and guess what?? It started right up and idled fine! It was giving the computer false info and was dumping way to much fuel at it. It was enough to stall the car at low speeds and make the car idle rough. Sometimes it would idle fine, others not. Please try this. It is an $80 part. Well worth it! BTW. on a different note, please check all tie rod ends on this model! They go bad easily. jack up car and feel for any play when grabbing the tire and turning the tire left and right. It should have none.

I would agree with what you've done , as there appears to be some discrepencies in the service manuals (all I have checked) with which MAP Sensor should be used on each vehicle. The problem is in their physical appearance , as well as : how many wires go into the inlet plug. For example : you have a 3 wire Map Sensor installed , while the manuals or other informations show a physically different shape of map sensor (which only has 2 wire connectors in the sensor , while there are 3 connectors on the intake).

Physically , the plastic moulding mount is different. If I remember correctly , some have 1 screw and a slot , while some clearly have 2 mounting screw holes in them. The main thing is that you match 3 connector types , with 3 connector intakes / plenum. I believe the 2 wire/pin types are for the 2.7L engine. But , like I said , I found that out when checking mine. Different , non-OEM parts may also be the problem , where the mounting is different , or the wrong part number is being used etc. This is why MOPAR suggests using OEM (Original Equipment Manufacturer) parts only. Some aftermarket parts makers may confuse you or sell you a conflicting part - if you don't pay attention to : how it mounts , and/or how many connecting pins must fit into the intake or receiving end. It's best to bring the part with you when buying , or checking a new part. In other words : it is possible you may have MAP Sensor problems , because the wrong part was installed. They will all fit.

To test your MAP Sensor : with the engine idling normally in PARK , while the engine is at normal temperature (not right after you get off the highway) , you fill a clean spray bottle with water : and spray around the MAP Sensor mount , to see if there is an airleak. Sometimes the gasket is hardened or cracked , which will make it so that you are loosing vacuum there. This can cause rough idle , and stalling. This is the service manual suggested procedure to physically test a MAP Sensor , or to quickly confirm a proper vacuum within the plug-in connector. If the engine stalls while you are spraying a fine spray of water to the mounting area seams - you have a vacuum leak. No air should be drawn from the outside air , into the intake.

This is not always the best way to diagnose stalling problems , because there could also be a problem at the throttle body intake / clogged air filters / leaking tube joints from the air filter inlet - to the intake throttle body , and other improper parts installations : such as - aftermarket , non-OEM sparkplugs , where there is a claim that they are superior. The engines are all tuned and calibrated to the OEM spark plugs , and if you think - buying suggested superior spark plugs is equivalent to being in a position to professionally ; manufacture / tune & calibrate the engine to a set of spark plugs. You might have problems , as many other 300M owners and others have found out in less than 1 month of driving.

If you unplug the MAP Sensor on any vehicle , the engine will stall or idle rough until it does. Plugging the MAP Sensor back in and restarting , could only produce results because the entire system was reset to a start condition. I am not saying that MAP Sensors are not the culprit , but there are many other things that can increase the MAP Sensor's ability to keep it's signals regular or within the calibrated range needed for proper idle / acceleration / deacceleration and air fuel / etc. mixture. Because all of them play a major role in sending signals to a computer etc. - which calculates and regulates the entire system. This applies to spark/timing , fuel and air intake as well. Usually , when you stop an engine , remove a part you suspect was not working , and replace the same part - and it appears the part is working correctly after restarting : that means the part was OK. But not always. All other possibilities must be checked , or else the problem will come back in a short period of time. This happens because the newer part is more efficient or better - but NOT the problem entirely , or at all. Incorrect sparkplugs alone can send you on a quest within the engine compartment , that leads to 12 or more parts being replaced / suspected , or unnecessarily tested. Engines without a distributor are very reliant upon the correct parts. So... why would you trust [E-best] [double spark] [wide ground] or any other nefarious sparkplugs , where PREMIUM LASER PLATINUM SPARK PLUGS ARE : OEM tested and calibrated to your specific engine?

In these categories alone , there is : Premium (above normal) , Laser (as fine and sharp a spark as you can get) , Platinum (durable & repeat performance) : and only available in this grouping from : (IE :NGK). 3 levels , where anything less can be detrimental. Air may not have anything to do with it. Excess fuel could be present because the wrong sparkplugs are installed. Unburned fuel = flooding/stalling/rough idle & poor fuel mileage. Notice also , that the BIG 3 dealerships , don't offer a multitude of aftermarket sparkplugs. The reason is clearly because they can't back up their use. And if you read your 300M owners manual - it suggests that the OEM sparkplugs are usually good for 60,000 miles or 100,000km. If this doesn't suggest to you that the OEM sparkplugs are good or a top performer for the said vehicle , then what will? While the 300M engines are : an all aluminum construction throughout the block and heads - don't you think using too hot or cold a sparkplug can cause engine damage? It can , and it will. It requires the correct sparkplugs , more than a cast iron block & head combination , of yesteryear engines.

After driving for a while and the car is warm and I stop and turn it off for approx 15 minutes and go to start again it sputters and most times it just dies. It takes a wait of about 10 minutes before it will sputter and start. After getting the rpm to about 2000 rpm it will run smooth and when I ease off the gas it runs fine.

It does not do sputter any other time. I had a mechanic plug his gizmo in and said the fuel pump showed no apparent problems and no sensor problem code came up?